Relief device for compressors.



R. CGNRADER.

RELIEF DEVICE FOR GOMPRESSORS.

APPLICATION FILED MAY 1, 1911.

1,089,397 v Patented Mar. 10, 1914.

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RUDOLPH CONRADER, OF ERIE, PENNSYLVANIA.

RELIEF DEVICE FOR COMPRESSORS.

Specification of Letters Patent.

Application filed May 1, 1911.

Patented Mar. 10,1914. Serial N 0. 624,306.

To all whom it may concern:

Be it known that I, RUDOLPH CoNRAoER, a citizen of the United States, residing at Erie, in the county of Erie Pennsylvania, have invented new and useful Improvements in Relief Devices for Compressors, of which the following is a specification.

This invention relates to relief devices for compressors and consists in certain improvements in the construction thereof as will be hereinafter fully described and pointed out in the claims.

More particularly the invention relates to a relief device adapted to operate upon the intake of a compressor.

One of the principal objects of the invention is to simplify this type of mechanism.

The invention is illustrated in the accompanying drawing wherein an end elevation of a compressor is shown with a relief device in section thereon.

1 marks the cylinder of the com ressor, 2 the intake and 3 the discharge. he relief device has the body 4 with the screw threaded ends 5 and 6. The body is divided by a diaphragm 7 through which is arranged the valve passage 8. The diaphragm divides the body-into the two chambers 9 and 10. A cylinder 11 extends from the body 4 and communicates directly with the chamber 10. The cylinder is connected by means of a pipe 1? with the discharge pipe 3 so that it is under receiver pressure at all times. The valve 13 operates on a seat surrounding the passage 8 and controls the passage of air through the relief device. The valve is carried by the piston 14, the piston being arranged in the cylinder 11. A counter pres sure device in the form of a spring operates against the piston 14. This spring extends through the valve passage 8 and into the screw threaded opening 17 in the body 4. A screw 16 is arranged in the screw threaded opening 17 and forms a base for the spring. The tension of the spring can be adjusted by means of the screw 16. The screw is provided with a hand wheel 18 by Which it may be readily operated and a lock nut 19 is provided for looking it in adjustment.

It will be observed that as the relief device is arranged in the drawings, the face of the valve 13 opposite the piston is subject to a pressure varying as the position of the valve varies, and more nearly approxiand State ofmating that in the chamber 9 as the valve approaches to closed position. Of course, when the valve is entirely closed, the face of the valve is subjected only to the pressure in the chamber 9. I utilize this varying of the pressure on the face of the valve in the con trol of the relief device, and by utilizing it, I am able to use a very short spring 15, and by reason of the varying pressure on the face of the valve, the effect of the increase in the tension of the spring as it is compressed is neutralized to some extent. On the other hand, if this face of the valve were the full size of the piston, the only pressure on the face side of the valve would be that of the intake which is approximately a vacuum when the valve is closed and this would require too large a pressure before the opening of the valve. I prefer to make the area of the face of the valve less than the area of the piston so that there is an area as at the shoulder 20 which is at all times subjected to atmospheric pressure, or the pressure in the chamber 10. By proportioning the area on the face of the valve and the shoulder, or proportioning area such a relation between the spring and the piston may be readily accomplished as desired. At the same time, arranging the spring through the valve passage as shown simplifies the mechanism very greatly as it eliminates glands or other packing devices in the mechanism for communicating the pressure of the spring to the piston.

By reversing this relief device, the face of the valve of the piston would be subjected to substantially atmospheric pressure while that part of the piston and valve represented by the shoulder 20 will be subjected to the reduced pressure of the chamber 10. There will therefore be somewhat the same action as where the valve is turned in the direction shown in the drawing. By proportioning the area of the shoulder 20 with the face of the valve a slight difference in the action of the device may be accomplished depending on which end of the relief device is attached to the intake, and therefore, a greater range of usefulness is accomplished. I, therefore, prefer to make the areas of the face of the valve and the piston such that there will be a variation in the action of the relief device with the opposite ends secured to the intake.

It will be noted that the cylinder 11 is directly connected with the discharge on the cylinder so that it is subjected at all times this difference in int to full receiver pressure and that the pressure on this piston varies with the receiver pressure.

What I claim as new is;

1. In a relief device for compressors, the combination of a compressor intake connection; a valve body having a passage therethrough; a valve seat; a valve operating on the seat by moving toward and from the seat and controlling the passage; a cylinder connected with the body; a piston in the cylinder for actuating the valve, said valve having a less area on the face exposed to the passage at the opposite side of the piston than the pitson; a receiver connection leading to the cylinder; and a spring operating against the piston;

2. In a relief device for compressors, the combination of a compressor intake connection; a valve body; a diaphragm dividing the body into two chambers, said diaphragm having a valve passage therethrough; a valve controlling said passage and opening and closing by movement from and toward the diaphragm; a cylinder connected with the body; a piston in the cylinder for actuating the valve, said valve having a less area next to the diaphragm than the piston; a receiver connection leading to the cylinder; and a spring operating against the piston.

3. In a relief device for compressors, the combination of a compressor intake connection; a valve body having a passage therethrough; a valve seat; a valve operating on the seat by moving toward and from the seatand controlling the passage; a cylinder connected with the body; a piston in the cylinder for'actuating the valve, said valve having a less area on the face exposed to the passage at the opposite side of the .piston than the piston but greater than one-half the area of the piston; a receiver connection leading to the cylinder; and a spring operating against the piston.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

RUDOLPH CONRADER.

Witnesses B. M. HARTMAN, J. J. SCHWARTZ. 

